This invention relates generally to the production of documents and the like having copy resistant characteristics and, more particularly, to copy resistant documents and to methods for treating or producing original documents in such a manner so as to yield easily readable documents under normal reading conditions but inhibiting, if not preventing, the reproduction of intelligible copies thereof by conventional copying processes.
Copying machines have become increasingly popular in recent years and can be found in most business offices and in public areas, such as shopping centers, hotel lobbies and the like. Because of the widespread availability of various types of copying machines, the ease with which they can be operated, and the low cost of each copy, virtually all documents are susceptible to being copied by anyone without the consent of the originator or owner. While the development of these copying machines certainly represents progress in the graphical communication field, they are often used to copy documents which may be abusive to the originator or owner. For example, the unauthorized and indiscriminate copying of materials such as news letters, poems, sheet music, drawings etc. may violate the legal rights of the publishers and/or authors denying to them the compensation to which they are entitled. Also, security can be flagrantly breached by copying material of a sensitive nature such as classified government information, industrial and commercial data, and personal correspondence of a confidential nature.